I like using od to see exactly what bytes are being sent: od -t x1 -N 1 will read one byte from stdin and print the hex representation, after you type it and hit enter.

I’ve often thought about ways to make a terminal that’s more modern, which mostly means the keyboard interaction isn’t atrocious out of the box. Oh, and colours makes sense. Of course it would have to be backwards compatible, as the author states, lest it never get used.

But I don’t think writing everything in Emacs Lisp is the way to go. I say this as a diehard Emacs, Lisp, and command line fan. For one thing, it doesn’t solve the wacky keyboard problem: a surjective mapping of keyboard input to output. C-= is the same as =.